I believe you can also specify in the contact record which line to use for outgoing calls. So your business contacts would use the business SIM and personal contacts the personal SIM.

But in response to the question by the created of this sub thread, I have not used that case, I've only used the eSIM for data only. If I get a chance to mess with it, I will try a variation of that next month, with my T-MO line moved to the eSIM and my German (FONIC) SIM as the physical SIM (and primary for data). Then I can receive calls/texts made to my US T-MO number and use my German number while in Europe.